What on Earth is Session Zero?

James Weatherall jnw "at" realvnc.com
Tue Nov 1 22:48:01 2005


Stephen,

1.  Can you explain what you mean by "as far as I can tell, the IP address
is correct"?  You must ensure that you are using the correct IP address,
either a LAN IP address (starting 192.168.) if connecting within a LAN, or
an Internet routable IP address (one NOT starting 192.168.) if connecting
across the Internet.

2.  VNC Server is *not* refusing connections, that is being done by your
operating system's network stack.

3.  What URL are you using when trying to download the Java viewer?

4.  Are you sure that you haven't selected the "Only allow connections from
local host" option in the VNC Server's Connections settings?

Regards,

Wez @ RealVNC Ltd.


> -----Original Message-----
> From: Stephen [mailto:stephen "at" sptv.demon.co.uk] 
> Sent: 01 November 2005 20:28
> To: James Weatherall
> Subject: Re: What on Earth is Session Zero?
> 
> 
> ----- Original Message -----
> From: "James Weatherall" <jnw "at" realvnc.com>
> To: "'Stephen'" <stephen "at" sptv.demon.co.uk>; <vnc-list "at" realvnc.com>
> Sent: Tuesday, November 01, 2005 2:18 PM
> Subject: RE: What on Earth is Session Zero?
> <snip>
> > As you will notice, I have specifically pointed out that 
> the problem 
> > you
> are
> > seeing is NOT related to Fast User Switching, nor to Remote 
> Desktop.  
> > The problem you are seeing indicates that the computer that 
> is using 
> > the IP address that you specify to VNC Viewer is NOT 
> listening for VNC
> connections.
> > This may be because:
> >
> > 1.  You are using the incorrect IP address for the server computer.
> 
> As far as I can tell the IP address is correct
> 
> > 2.  There is no VNC Server running on the server computer.
> 
> The VNC Server is definitely running. It is listed when I run 
> netstat -a which says it is listening on the correct ports, 
> even though it refuses all connections.
> 
> > 3.  There is a firewall in place around/on the server 
> computer that is 
> > rejecting the connections.
> 
> All firewalls have been disabled.
> 
> > 4.  You are testing connecting via a NAT router from a 
> machine on the 
> > same LAN as the server - many new NAT routers are broken and won't 
> > allow this.
> 
> I am connecting via the internet from a location 50 miles 
> away from the XP PC. The Windows ME PC on the same router at 
> the same remote location has always worked with Real VNC, and 
> still does. The exact same Real VNC software, using the same 
> or equivalent settings, on the same router with all firewalls 
> disabled, refuses all incoming connections on the XP PC.
> 
> > The fact that you say "no, I am not using the same port number" 
> > suggests that perhaps your router's port forwarding 
> configuration at 
> > the server end is the problem - you'll need to make sure 
> that you are 
> > specifying the correct external port number to VNC Viewer, 
> and having 
> > that forwarded to
> the
> > port number on which your VNC Server is listening for connections.
> 
> The viewer and server are set for the same port number, and 
> the router is set to allow all incoming connections to both 
> PCs. This arrangement works with the ME PC.
> 
> > Are you testing connections using VNC Viewer for Java, or a 
> native VNC 
> > Viewer?
> 
> I am using the native VNC viewer. I have also tried the VNC 
> viewer for Java. This doesn't work, and the java applet does 
> not download from the XP machine. (It does work from the ME 
> machine, as does the native VNC viewer.)
> 
> > VNC Server works fine on Windows XP Home Edition.
> 
> I hope to be able to prove this for myself, as the PC I need 
> to control remotely is the XP one.
> 
> >
> > Cheers,
> >
> > Wez @ RealVNC Ltd.
> >
> >
> >
> > > -----Original Message-----
> > > From: vnc-list-admin "at" realvnc.com 
> [mailto:vnc-list-admin "at" realvnc.com] 
> > > On Behalf Of Stephen
> > > Sent: 01 November 2005 11:50
> > > To: vnc-list "at" realvnc.com
> > > Subject: What on Earth is Session Zero?
> > >
> > > I am getting really really fed up with RealVNC. All it will ever 
> > > ever do is say Connection Refused Eror 10061, and yes I 
> have checked
> > > every single thing
> > > to do with firewalls over and over again, all firewalls are
> > > completely off,
> > > RealVNC viewer and server are exceptions in Windows Firewall
> > > list anyway.
> > > The exact same system works with a Windows ME PC on the same
> > > router, and no
> > > the other PC is not switched on, and no I do not use the same
> > > port number,
> > > yes the server is running on the XP PC, yes I am accessing
> > > the right PC.
> > >
> > > It DOES work if I phone someone at the other end and get them to 
> > > initiaite the connection with "Add New Client", but it is never
> > > possible to connect
> > > from my end with RealVNC viewer, or http in Internet
> > > Explorer. Because "Add
> > > New Client" is the only thing that has ever worked, it means
> > > that the full
> > > extent of the usefulness of RealVNC is that it can be 
> used if there is
> > > someone at the other end 24 hours a day who can be contacted
> > > by phone to Add
> > > New Client manually to initiate the connection. This is not
> > > how we want
> > > remote control software to work.
> > >
> > > I e-mailed Real VNC's help and support explaining the reality of 
> > > Real VNC for the ordinary (XP Home) user, "it is a piece 
> of software
> > > which can and
> > > does do only one thing: put a message on the screen which
> > > says "Connection
> > > Refused" - in the REAL world RealVNC does not work." 
> Their reply was,
> > > "current releases of VNC Server will only allow session zero
> > > to be accessed
> > > remotely, and this may best be ensured by disabling Fast User
> > > Switching nor
> > > Remote Desktop in some cases. Disabling these features is
> > > described in the
> > > Windows XP documentation, which may be accessed via the "Help
> > > and Support"
> > > entry in the Start Menu of your Windows XP system."
> > >
> > > I have disabled Fast User Switching and Remote Desktop, 
> and it has 
> > > made no difference at all. What difference should it make? How is
> > > anyone supposed to
> > > know what SESSION ZERO is? What is it? I see no mention of
> > > session zero in
> > > Real VNC or in Windows XP Help. If attempting to get RealVNC
> > > to work relies
> > > on an understanding of the meaning of "Session Zero", 
> then no ordinary
> > > computer user can ever be expected to
> > > use RealVNC.
> > >
> > > Can someone please point me in the direction of a remote control 
> > > Server which DOES work on Windows XP Home Edition? NOT Real VNC 
> > > Server, NOT TightVNC Server (I have been down the same path with 
> > > this and it also refuses to connect), NOT Windows Remote Desktop 
> > > Server (deliberately disabled by Microsoft in XP Home 
> Edition), NOT 
> > > Microsoft Netmeeting Server
> > > (also deliberately disabled by Microsoft in XP Home Edition.)
> > > Is my problem
> > > because this deliberate disabling also disables Real VNC Server?
> > >
> > > It seems to me that RealVNC IS NOT COMPATIBLE WITH 
> WINDOWS XP HOME 
> > > EDITION and should not be advertised as though it is. Has anyone 
> > > EVER had the remote
> > > control Server running correctly and accepting connections on
> > > Windows XP
> > > HOME Edition?
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